Connect with TRB

To account for different variables related to traffic, climate and materials, and their interactions affecting pavement performance, a research effort initiated by the National Cooperative Highway Research Program (NCHRP) has led to the development of a Mechanistic-Empirical Pavement Design Guide (MEPDG),
documented in NCHRP Report 01-37A (2004). This MEPDG method is being
adapted by the Wyoming Department of Transportation (WYDOT) for roadway designs. However, the default input variables recommended in the MEPDG were
developed based on national conditions that do not reflect the local Wyoming conditions. Due to potential differences between national and local conditions and the significant influence of input data on the precision of pavement design using the MEPDG, many states have already instituted calibration procedures and developed calibration methods for partial or full calibration of the MEPDG on a local level (Hall 2010).
Since the subgrade resilient modulus is an essential parameter for computing stresses and deformations, induced in the pavement structure by applied traffic loads, correlation studies have been conducted to develop methods to estimate the resilient modulus as summarized in Error! Reference source not found. (i.e., Models C to F). However, similar predictive models based on DCP and SPT have not been developed, and they would be a valuable tool for in-situ quantification of the resilient modulus of an existing subgrade material in a road rehabilitation project. Additionally, it is important to quantitatively compare and contrast different predictive models in terms of their respective pavement performance estimations so as to provide transportation agencies, like WYDOT, necessary recommendations for the selection of predictive models that fit a particular application. Also, these data and results can be included into the existing Wyoming Pavement Management System (PMS) to facilitate full implementation of MEPDG in Wyoming.
Although the ongoing research provides locally calibrated input parameters for MEPDG pavement design, it is indispensable to evaluate the sensitivity of thickness and modulus of pavement materials on pavement performance predictions. This additional study will help designers and engineers optimizing their pavement designs and facilitating the iterative design process while using MEPDG design software known as DARWin-METM. Although the current state-of-practice is switching towards AASHTOWare Pavement ME Design, DARWin-METM is considered to reflect local design practices. Knowledge from the ongoing research and results from this proposed research should be integrated and presented through a series of trial pavement design examples that systematically articulate the whole pavement design process. The proposed 2-year research serves MEPDG research. This proposed research will enhance the pavement design procedure and efficiency, overcome shortcomings of the ongoing research, and expedite the full implementation of locally calibrated MEPDG in Wyoming.